METHOD FOR MANUFACTURING NONVOLATILE SEMICONDUCTOR MEMORY DEVICE AND STRUCTURE THEREOF

摘要

PURPOSE: A method for fabricating a floating gate of a nonvolatile semiconductor memory device and a structure thereof are to reduce a size of a sidewall spacer for patterning the floating gate, and to prevent a decrease of a device isolating characteristic of a field region. CONSTITUTION: A trench device isolating layer(102) is formed at a predetermined region of a semiconductor substrate(100). The first polycrystalline silicon layer(104) is formed on the semiconductor substrate with the trench device isolating layer formed thereon at a thickness of about 1000 angstroms. An anti-reflection layer is formed on the first polycrystalline silicon layer to prevent a damage in the first polycrystalline silicon layer from a photo process. A photoresist pattern is formed only on the anti-reflection layer to be formed with a floating gate. The anti-reflection layer and the first polycrystalline silicon layer are etched at a predetermined depth using the photoresist pattern as an etching mask. The second polycrystalline silicon layer is formed on the entire surface of the resultant structure. A sidewall spacer(110-1) is formed on the sidewall of the first polycrystalline silicon layer stepped by the etching process using the photoresist pattern.